I can understand you being angry. It sounds like he is dry simply because your broke. Being supportive need be no more complicated than not nagging and constantly questioning his intentions regarding sobriety.
Why not give this forum a try as your supporrt? Commit to spending a little time here everyday reading and posting.
AA and rehab can be great tools in recovery but it really has to be something he wants. Does he want to get better? Does he want lasting sobriety?